DEFINITION OF TiENIA CUCUMEEINA. 665 



from Davaine that these bodies are not separate eggs, as Greuet sup- 

 posed, but masses of eggs, which are embedded in and enveloped by 

 a common cementing substance of a firm (apparently chitinous) nature, 

 this comparison is all the more apt ; and, moreover, the cementing 

 substance, just as in the leech, is continued externally into a fibrous 

 tissue, the principal stems of which assume a radial direction, fre- 

 quently anastomosing and uniting to form a spongy coating. Between 

 the ramifications there are a few calcareous corpuscles, which are 

 indeed sparsely distributed over the whole parenchyma of the body. 



In some respects this spongy coating recalls the border of rods in 

 the egg-shell of the cystic tape- worms. Like the latter, it increases 

 the vitality of the egg, and probably also serves to preserve it from 

 desiccation. 



Group C. The proglottides have two peripheral sexual openings 

 opposite to each other, leading to a male and female efferent apparatus, 

 the latter of which possesses, in addition to the receptacidum, a special 

 germ-gland. The proioscides are oval or spherical, and are provided 

 with a number of rows of small hooks, which, instead of roots, have a 

 discoidal iase. After the development of the embryo, the eggs become 

 cemented together into rather large groups. 



Subgenus Dipylidium, Leuckart. 



Fig. 346. — Head of Taenia cucumerina, with rostellum and hooks, in diflterent 

 stages of contraction. ( x 140.) 



A small group of tape-worms, which, according to the definition 

 just given, includes only a single species parasitic in the cat and the 

 dog, but which would be considerably increased were we to regard 

 only the presence of two peripheral pori. 



Taenia cucumerina, Eudolphi. 



(Incl. Tffinia elliptica, Batsch.) 



In a ripe condition has usually a length of 18 to 25 cm., and in 

 the posterior joints a breadth of IS to 2 mm. The anterior end of the 

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